1. Field of the Invention
The present invention relates to a novel nucleic acid encoding β-1,3-glucanase from lily, the polypeptide encoded therefrom and their applications.
2. Description of the Prior Art
Plants have evolved many mechanisms against pathogen attack such as hypersensitive response (HR), systemic acquired resistance (SAR), and induced systemic resistance (ISR). Plant defense response are generally accompany with the expression of genes encoding pathogenesis-related proteins (PR proteins). Some of the PR proteins have enzymatic activities, such as glucanases. For instance, Kauffmann, S. et al. indicated that four of PR proteins of tobacco have, β-1,3-glucanase activity (Kauffmann et al., 1987, EMBO J. 6: 3209–3212)
Plant β-1,3-glucanase is a hydrolytic enzyme that is abundant in various plant species of monocots and dicots. Some glucanases of plant origin are capable of inhibiting the growth of fungi (Sela-Buurlage et al., 1993, Plant Physiol. 101: 857–863). A purified β-1,3-glucanase from soybean (Keen & Yoshikawa, 1983, Plant Physiol. 71: 460–465) has been shown to be capable of degrading isolated cell walls of fungi in vitro. Recently, overexpression of β-1,3-glucanase in plants was shown to be capable of resisting infection by fungal pathogens (Lusso & Kuć, 1996; Physiol. Mol. Plant Pathol. 49: 267–283; Masoud et al., 1996, Transgenic Res. 5: 313–323; Nakamura et al., 1999, Plant Cell Reports 18: 527–532). In addition, EP 440304 provided plants having improved resistance against pathogenic fungi, which are transformed with at least one gene encoding an intracellular chitinase, or in intra- or extracellular β-1,3-glucanase.
The genes expressing β-1,3-glucanase have been widely studied. Simmons, C. R. disclosed the physiology and molecular biology of plant 1,3-β-D-glucanases and 1,3; 1,4-β-D-glucanases (Simmons, C. R., 1994, Critical Rev. Plant Sci. 13:325–387). U.S. Pat. No. 6,066,491 indicated that after a necrotic infection, the enzyme can often be found throughout the plant, including the non-infected parts, in higher concentrations than before infection; Increased synthesis of the enzyme appears to be induced also by microbial elicitors, usually fungal cell wall preparations. Tissue-specific and pathogen-induced regulation of a Nicotiana plumbaginifolia β-1,3-glucanase gene has been found (Castresana et al., 1990, Plant Cell 2: 1131–1143). Moreover, Thimmapuram et al. (2001) and Maher et al. (1993) researched the characterization and expression of β-1,3-glucanase genes in peach and alfalfa, respectively, and found the pathogen-inducible trait (Mol. Gen. Genet. 265:469–479; Physiol. Mol. Plant Pathol. 43: 329–342). Renault et al., 2000 demonstrated the expression of β-1,3-glucanase in grapevine leaves after fungal infection (Am. J. Enol. Vitic. 51: 81–87). In addition, Didierjean L. et al. (1996), reported that β-1,3-glucanase is increased when the corn leaf is stimulated by non-biological conditions (Planta 199:1–8). WO 92/16632disclosed a recombinant DNA sequence derived from soybean which codes for a novel protein with, β-1,3-glucanase activity.
It is still a need to further develop new nucleic acid expressing β-1,3-glucanase.